JP7123691B2 - Bottom mold and method for manufacturing glass container using bottom mold - Google Patents

Description

The present invention relates to a bottom mold for molding glass containers. The bottom mold according to the invention forms part of the mold used in blow molding to form glass containers from parisons.

As a mold for molding a glass container from a parison, a mold having a bottom mold for forming the bottom of the glass container and a pair of finishing molds arranged above the bottom mold and forming the sides of the glass container is known. is. In order to form an upwardly bulging push-up (so-called bottle bottom dent) in the bottom of the glass container, a convex portion protruding upward is formed in the center of the bottom mold (see, for example, Patent Document 1). ).

Patent No. 4170970 specification

If the protrusion provided in the center of the bottom mold is raised to increase the height of the push-up, the contact area between the protrusion and the glass increases. Therefore, the amount of heat transferred from the glass to the projections increases, and the temperature of the tips of the projections rises. When the temperature of the tip of the protrusion becomes high, there arise problems that the molded glass container becomes difficult to separate from the protrusion and that microcracks occur. To solve this problem, in order to lower the temperature of the tip of the protrusion, the entire bottom mold is made of a material with high thermal conductivity, or the cooling air supplied to the bottom mold is increased to cool the bottom mold. If the strength is strengthened, the temperature of the base (root) of the convex portion of the bottom mold decreases and the temperature of the glass surface becomes too low, so defects such as microcracks are likely to occur at the bottom of the glass container after molding. In addition, the lowering of the temperature of the base portion (root portion) of the projection hinders the stretching of the glass, resulting in poor molding. In general glass container molding, the temperature at the tip of the projection is preferably 600° C. or less in consideration of releasability, and the temperature at the base of the projection is determined in consideration of push-up moldability. It is desirable that the temperature be 500° C. or higher and 600° C. or lower, and more preferably 530° C. or higher and 550° C. or lower. Therefore, a technique is required to maintain the temperature of the base of the projection at 500° C. or more and 600° C. or less and lower the temperature of the tip of the projection to 500° C. or more and 600° C. or less.

In view of the above background, the present invention provides a bottom mold for molding a glass container, in which the temperature rise at the tip of the convex portion is suppressed while suppressing the temperature drop in the base portion of the convex portion provided in the center. is the subject. Another object of the present invention is to form a push-up on the bottom of a glass container while suppressing microcracks and molding defects. Another object of the present invention is to provide a method of manufacturing a glass container capable of forming a push-up on the bottom while suppressing microcracks and molding defects.

In order to solve the above problems, one aspect of the present invention is a bottom mold (15) that is used for blow molding to mold a glass container (C) from a parison and molds the bottom of the glass container, wherein the bottom The mold has a projection (36) projecting upward from the center of the mold and corresponding to the center of the bottom of the glass container, and the base (38) of the projection is made of a first material. , the tip (37) of the projection is made of a second material having a higher thermal conductivity than the first material.

According to this aspect, since the thermal conductivity of the tip of the protrusion is higher than that of the base, the heat of the tip of the protrusion, which is in contact with the glass (parison) for a long time and reaches a high temperature, is cooled. It can be efficiently lowered by the wind. Therefore, after the glass container is molded, the temperature of the tip of the projection can be lowered to the optimum temperature before the next glass is placed. As a result, it is possible to suppress the temperature rise at the tip of the projection and suppress the temperature drop at the base of the projection without increasing the cooling airflow. As a result, the releasability of the bottom mold from the molded glass container can be improved while appropriately molding the glass container.

In the above aspect, the base of the protrusion has a receiving hole (44) in the center, and the tip of the protrusion includes a shaft (51) inserted into the receiving hole and the shaft (51). and a head portion (52) provided at one end of the portion and forming a central portion of the bottom portion of the glass container.

According to this aspect, it is possible to simplify the assembly structure of the tip of the projection and the base of the projection, which are formed of different materials. Moreover, the heat received by the head portion can be transferred to the inside of the bottom mold by the shaft portion, and the temperature of the surface of the tip portion of the convex portion that contacts the glass container can be lowered.

Moreover, said aspect WHEREIN: It is good to protrude the said head to the said glass container side with respect to the said base of the said convex part.

According to this aspect, the bottom portion of the glass container to be formed can be formed by the head portion and the base portion of the convex portion.

In the above aspect, a cooling passage (41) through which a cooling medium flows is formed inside the bottom mold below the convex portion, the receiving hole is connected to the cooling passage, and is connected to the other end of the shaft portion. projects into the cooling passage.

According to this aspect, since the shaft is cooled by the cooling medium, it is possible to lower the temperature of the surface of the tip of the protrusion that is in contact with the glass container.

Further, in the above aspect, the other end of the shaft portion preferably has a plurality of cooling fins (61).

According to this aspect, the heat dissipation of the shaft can be improved, and the temperature of the surface of the tip of the protrusion that contacts the glass container can be further reduced.

In the above aspect, the end of the receiving hole on the side of the cooling passage is wider than the opposite end, and preferably forms a gap (56) with the shaft.

According to this aspect, the exposed area of the shaft portion to the cooling passage can be increased, and the shaft portion can be further cooled.

In the above aspect, the shaft portion may be press-fitted into the receiving hole.

According to this aspect, it is possible to simplify the assembling structure of the tip portion and the base portion of the projection formed from different materials.

Moreover, in the above aspect, it is preferable to have a retainer pin (58) that extends in the radial direction of the shaft, penetrates through the base of the protrusion, and is engaged with the shaft.

According to this aspect, it is possible to prevent the tip of the protrusion from falling off from the base.

Further, in the above aspect, the tip portion of the convex portion may be a sprayed portion (71) thermally sprayed to the base portion of the convex portion.

According to this aspect, the tip of the projection and the base of the projection, which are made of different materials, can be integrally formed.

In the above aspect, the first material may be an iron-based material, and the second material may be a copper-based material.

According to this aspect, the thermal conductivity of the tip of the protrusion can be made higher than that of the base of the protrusion.

Another aspect of the present invention is a glass container (C) manufactured using the bottom mold (15) described above, characterized in that it has a push-up (P) on the bottom.

According to this aspect, it is possible to form a push-up on the bottom of the glass container while suppressing microcracks and molding defects.

Another aspect of the present invention is a method for manufacturing a glass container (C) using the bottom mold (15), wherein the temperature of the tip portion and the base portion of the convex portion is set to 500° C. or more and 600° C. or less. It is characterized by comprising a step of pressing glass having flexibility at a temperature of 700° C. or more and 1000° C. or less against the bottom mold. Further, in the method for manufacturing the glass container (C) using the bottom mold (15), the temperature of the tip of the projection is adjusted to 550° C. or more and 600° C. or less, and The method is characterized by comprising a step of adjusting the temperature of the base to 500° C. or more and 550° C. or less, and pressing glass having flexibility of 700° C. or more and 1000° C. or less against the bottom mold.

According to this aspect, it is possible to form a push-up at the bottom of the glass container while suppressing microcracks and thickness defects.

Advantageous Effects of Invention According to the present invention, in a bottom mold for molding a glass container, it is possible to suppress a temperature rise at the tip of a projection while suppressing a temperature drop at the base of a projection provided in the center. Further, in a glass container, it is possible to form a push-up at the bottom while suppressing microcracks and molding defects. Moreover, it is possible to provide a method for manufacturing a glass container that can form a push-up on the bottom while suppressing microcracks and molding defects.

The side view which shows the molding apparatus which concerns on embodiment Sectional view showing distributor plate, bottom die and finishing die Cross section of bottom mold Sectional view of a bottom mold according to a modified embodiment

Embodiments of the present invention will be described below. The glass container molding apparatus according to the present embodiment performs a process of molding a parison from a glass gob and a process of molding a glass container from the parison.

As shown in FIG. 1, the molding apparatus 1 has a reversing arm 3 rotatably supported on a base 2. As shown in FIG. The reversing arm 3 has a center of rotation extending in the horizontal direction, and rotates between an initial position and a reversing position rotated 180° with respect to the initial position. At least one mouth mold 4 is supported at the tip of the reversing arm 3 . The mouth mold 4 is arranged above the reversing arm 3 when the reversing arm 3 is in the initial position. Each mouth die 4 has a split die having mating surfaces extending vertically, and a guide ring arranged between the pair of split dies. Each of the pair of split molds and guide ring is supported by the reversing arm 3 . The base is provided with a plunger that passes through the guide ring and enters between the split molds when the mouth mold is in the initial position.

A pair of rough dies 5 are arranged above each mouth die 4 . A pair of rough dies 5 have mating surfaces extending vertically, and are arranged so as to sandwich the mouth die 4 from the sides at their lower ends. A pair of rough dies 5 form a shape corresponding to the side of the parison on the mating surfaces. An upper end opening of the rough mold 5 is closed by a baffle 6 so as to be openable and closable.

The step of molding the parison from the glass gob is performed, for example, by blow-and-blow molding. First, the gob is put into the mouth mold 4 and the rough mold 5 with the baffle 6 retracted. Next, the upper end of the rough mold 5 is closed by the baffle 6, and settle air is jetted from the baffle 6 to press the gob against the mouth mold 4 to form the mouth of the parison. Next, air is injected into the mouth from between the split mold and the plunger of the mouth mold 4 to expand the gob, and the gob is pressed against the rough mold 5 and baffle 6 to form the side and bottom parts of the parison. This forms a parison. Next, the baffle 6 and the plunger of the mouth die 4 are retracted, and the pair of rough dies 5 are opened to expose the parison. In this state, the parison is supported by the mouth mold 4 at the mouth. By moving the reversing device to the reversing position, the parison is reversed so that the mouth portion is positioned at the upper end, and is suspended from the mouth model 4 . In other embodiments, instead of blow-and-blow molding, the parison may be formed by press-and-blow molding or narrow-neck press-and-blow molding.

A distributor plate 10 is provided on the base 2 below the mouth die 4 in the inverted position. As shown in FIG. 2, the distributor plate 10 is a plate-like member made of metal such as iron, and has a horizontal upper surface 11 . A bottom mold 15 for forming the bottom of the glass container C is arranged on the upper surface 11 of the distributor plate 10 .

The upper surface 11 of the distributor plate 10 is recessed with a first support hole 16 which is a bottomed circular hole. A cylindrical support shaft 17 is detachably fitted in the first support hole 16 . The upper end of the support shaft 17 protrudes above the upper surface 11 . An exhaust passage 18 is formed through the support shaft 17 in the axial direction.

A positioning pin 20 protrudes from the upper surface 11 of the distributor plate 10 . The distributor plate 10 is formed with a plurality of first vent holes 23 that penetrate in the thickness direction (vertical direction) and open to the upper surface 11 . Further, the distributor plate 10 is formed with a second ventilation hole 24 that penetrates in the thickness direction (vertical direction), opens to the bottom of the first support hole 16 , and is connected to the exhaust passage 18 .

As shown in FIG. 2 , the bottom mold 15 has a bottom plate portion 25 . The bottom plate portion 25 is formed in a substantially disk shape and has horizontal upper and lower surfaces. In the center of the lower surface of the bottom plate portion 25 , a second support hole 26 which is a bottomed circular hole is recessed along the center axis A of the bottom mold 15 . The second support hole 26 is formed so that the support shaft 17 can be fitted therein. A fitting hole 28 into which the positioning pin 20 is fitted is formed in the lower surface of the bottom plate portion 25 . The position of the bottom die 15 with respect to the distributor plate 10 is determined by fitting the support shaft 17 into the second support hole 26 and fitting the positioning pin 20 into the fitting hole 28 .

At the center of the upper surface of the bottom plate portion 25 , a cylindrical bottom mold lower portion 31 protruding upward along the center axis A of the bottom mold 15 is provided. A bottom mold upper portion 32 is coaxially provided at the upper end of the bottom mold lower portion 31 . The bottom mold upper portion 32 is formed in a disc shape centered on the central axis A, and its outer peripheral portion protrudes radially outward from the bottom mold lower portion 31 . The upper surface of the bottom mold upper portion 32 constitutes a bottom mold surface 33 corresponding to the bottom of the glass container C to be molded.

A concave portion 35 that is recessed downward is formed in the outer peripheral portion of the bottom mold surface 33 . The recessed portion 35 extends annularly around the central axis A. As shown in FIG. A convex portion 36 protruding upward along the center axis A is formed in the central portion of the bottom mold surface 33 . The convex portion 36 is formed in a substantially conical shape centering on the central axis A. As shown in FIG. The convex portion 36 has a tip portion 37 formed in a blunt hemispherical shape (convex surface) and a base portion 38 (root portion) located below the tip portion. The outer peripheral edge of the base 38 is smoothly connected to the inner peripheral edge of the recess 35 . The convex portion 36 corresponds to the central portion of the bottom portion of the glass container C, and forms a push-up P (recess) in the central portion of the bottom portion of the glass container C. As shown in FIG.

A cooling cavity 41 (cooling passage) through which air flows as a cooling medium is formed inside the bottom mold lower portion 31 and the bottom mold upper portion 32 . The cooling cavity 41 is arranged below the projection 36 . The cooling cavity 41 is connected with the second support hole 26 . A plurality of third ventilation holes 42 extending from the lower surface of the bottom plate portion 25 to the cooling cavity 41 are formed in the bottom mold lower portion 31 and the bottom plate portion 25 . When the bottom mold 15 is set on the distributor plate 10 , the opening end of each third ventilation hole 42 on the bottom plate portion 25 side is connected to the opening edge of the corresponding first ventilation hole 23 on the upper surface side. Below the distributor plate 10 , a ventilation port is provided for supplying cooling air (compressed air) to the lower end of the first ventilation hole 23 . The cooling air passes through the first air hole 23 and the third air hole 42 and flows into the cooling cavity 41 to cool the bottom mold 15 . After that, the cooling air is discharged outside from the cooling cavity 41 through the exhaust passage 18 and the second ventilation hole 24 . Also, some of the plurality of first air holes 23 open toward the bottom surface of the bottom plate portion 25 to cool the bottom surface of the bottom plate portion 25 .

A base portion 38 of the convex portion 36 is made of a first material, and a tip portion 37 of the convex portion 36 is made of a second material having higher thermal conductivity than the first material. The first material may be a ferrous material such as gray cast iron, ductile cast iron, carbon steel, alloy steel, carbon tool steel, and alloy tool steel. The second material may be a copper-based material such as copper and copper alloys. The copper alloy may be a known copper alloy such as cupronickel, nickel silver, aluminum bronze, and the like. Alternatively, the second material may be an aluminum alloy. In this embodiment, the bottom mold lower portion 31 of the bottom mold 15 and the bottom plate portion 25 are integrally formed of the same first material as the base portion 38 of the projection 36 .

As shown in FIG. 3, the base 38 of the protrusion 36 has a receiving hole 44 in the center. The receiving hole 44 extends vertically along the central axis A and has a lower end connected to the cooling cavity 41 and an upper end open to the upper surface of the base 38 of the projection 36 . The receiving hole 44 has a widened portion 45 at the end (lower end) on the side of the cooling cavity 41 that is widened stepwise. Due to the widened portion 45 , the end (lower end) of the receiving hole 44 on the side of the cooling cavity 41 is wider than the opposite end (upper end). A seat surface 46 is formed around the receiving hole 44 on the upper surface of the base portion 38 of the convex portion 36 . The seat surface 46 has an annular shape and is formed on a plane perpendicular to the central axis A. As shown in FIG.

A distal end portion 37 of the convex portion 36 is formed by an insert body 50 having a shaft portion 51 inserted into the receiving hole 44 and a head portion 52 provided at the upper end of the shaft portion 51 . The head 52 is formed in a hemispherical shape and has a convex upper surface 53 and a planar lower surface 54 . Head 52 has a larger diameter than shank 51 and is provided coaxially with shank 51 . The tip portion 37 of the protrusion 36 is attached to the base portion 38 of the protrusion 36 by press-fitting the shaft portion 51 into the receiving hole 44 . The head portion 52 protrudes toward the glass container C with respect to the base portion 38 of the convex portion 36 when the tip portion 37 of the convex portion 36 is attached to the base portion 38 of the convex portion 36 . The lower surface 54 of the head 52 contacts the seat surface 46 , and the upper surface 53 of the head 52 forms a curved surface that smoothly continues to the outer surface of the base 38 of the projection 36 . A gap 56 is formed between the inner peripheral surface of the widened portion 45 of the receiving hole 44 and the outer peripheral surface of the shaft portion 51 .

The insertion body 50 (the distal end portion 37 of the convex portion 36 ) is fixed to the base portion 38 of the convex portion 36 by a retaining pin 58 . The retaining pin 58 extends in the radial direction of the shaft portion 51 , passes through the base portion 38 of the protrusion 36 , and engages with the shaft portion 51 at one end. The retaining pin 58 is preferably inserted into an insertion hole 59 formed in the base portion 38 of the projection 36 and fixed to the insertion hole 59 by press fitting or welding. The open end of the insertion hole 59 is filled by welding or the like after the retaining pin 58 is attached.

The tip (lower end) of the shaft portion 51 protrudes into the cooling cavity 41 . A tip of the shaft portion 51 has a plurality of cooling fins 61 . Each cooling fin 61 extends in the circumferential direction along the outer peripheral surface of the shaft portion 51 . Various known shapes can be applied to the cooling fins 61 , and the cooling fins 61 may extend axially along the outer peripheral surface of the shaft portion 51 or may be spirally provided on the outer periphery of the shaft portion 51 .

During molding, the temperature of the tip 37 of the convex portion 36 is preferably 600° C. or less in consideration of the releasability of the glass. Also, the temperature of the base portion 38 of the convex portion 36 is preferably 500° C. or higher in consideration of the moldability of the glass. The tip portion 37 has a higher temperature than the base portion 38 due to its position relative to the glass, but the temperature difference with the base portion 38 is preferably small. From the above point of view, it is preferable that the temperature of the tip portion 37 of the convex portion 36 is set to 550° C. or higher and 600° C. or lower, and the temperature of the base portion 38 is set to 500° C. or higher and 550° C. or lower during molding. The glass (parison) pressed against the bottom mold 15 has a temperature of 700° C. or more and 1000° C. or less and has flexibility.

A positioning pin 62 protruding upward is provided on the upper surface of the bottom plate portion 25 . A pair of finishing dies 64 are arranged above each bottom die 15 . The finishing die 64 is made of metal such as gray cast iron. The pair of finishing dies 64 has mating surfaces extending vertically, and has side mold surfaces 65 corresponding to the shape of the sides of the glass container C to be formed on the mating surfaces. Each side mold face 65 defines a finished mold cavity 66 . The lower end surfaces of the pair of finishing dies 64 are formed into flat surfaces capable of sliding contact with the upper surface of the bottom plate portion 25 . A first clamping portion 68 that clamps the bottom mold lower portion 31 and the bottom mold upper portion 32 of the bottom mold 15 is formed at the lower end edge of the side mold surface 65 of each finishing mold 64 . A second clamping portion 69 that clamps the positioning pin 62 is formed at the lower end of the mating surfaces of the pair of finishing dies 64 .

The pair of finishing dies 64 are supported by a support device (not shown) and move between a molding position where their mating surfaces are in contact with each other and a retracted position where their mating surfaces are separated from each other and away from the bottom mold 15. It is possible. For example, the pair of finishing dies 64 may move between the molding position and the retracted position by pivoting about a predetermined vertical axis.

When the pair of finishing dies 64 are at the molding position, the bottom mold lower portion 31 and the bottom mold upper portion 32 of the bottom mold 15 are clamped by the first clamping portion 68 and the positioning pin 62 is clamped by the second clamping portion 69 . Thereby, the relative positions of the pair of finishing dies 64 and the bottom dies 15 are determined. When each finishing mold 64 is in the molding position, the bottom mold surface 33 and the side mold surfaces 65 are smoothly connected to form a shape corresponding to the outer shape of the glass container C to be molded.

In the manufacturing method of the glass container C, in the step of forming the glass container C from the parison, the parison supported by the mouth mold 4 is first moved above the bottom mold 15 by moving the reversing arm 3 to the reversing position. It is in a state of being suspended by the mouth mold 4. Next, the finishing mold 64 is moved to the molding position and placed above the bottom mold 15 . At this time, the bottom mold lower portion 31 and the bottom mold upper portion 32 of the bottom mold 15 are clamped by the first clamping portion 68, and the positioning pin 62 is clamped by the second clamping portion 69, whereby the position of the bottom mold 15 is fixed. be done.

By placing the finishing dies 64 in the molding position, the parison is placed in the finishing die cavity 66 between the finishing dies 64 and the mouth die 4 is placed in the upper end opening of the finishing die cavity 66 . Next, the mouth portion of the glass container C with the molded mouth shape 4 is released, and the reversing arm 3 moves to the initial position. A compressed air supply nozzle is then connected to the mouth of the parison. The temperature of the parison at this time is 700° C. or more and 1000° C. or less. In this state, compressed air is blown into the inside of the parison through the mouth of the parison to inflate the parison downward and laterally. The parison is pressed against the bottom mold surface 33 of the bottom mold 15 and the side mold surfaces 65 of the finishing mold 64 to form a glass container C having a push-up P on the bottom. During molding of the glass container C, the temperature of the tip portion 37 and the base portion 38 of the convex portion 36 is set to 500° C. or more and 600° C. or less. More preferably, the temperature of the tip portion 37 of the protrusion 36 is set to 550° C. or higher and 600° C. or lower, and the temperature of the base portion 38 is set to 500° C. or higher and 550° C. or lower.

Next, each finishing mold 64 is moved to the retracted position, and the bottom of the glass container C is supported by the bottom mold 15 . From this state, a clamping device (not shown) clamps the mouth of the molded glass container C and lifts the glass container C upward to separate the bottom of the glass container C from the bottom mold 15 . The glass container C removed from the bottom mold 15 by the clamping device is sent to the subsequent annealing step.

The effect of the bottom mold 15 configured as above will be described. Since the tip portion 37 (insertion body 50 ) of the convex portion 36 is made of a material having a higher thermal conductivity than the base portion 38 , the heat of the tip portion 37 is easily transferred to the base portion 38 . As a result, it is possible to suppress the temperature rise of the tip portion 37 while suppressing the temperature drop of the base portion 38 . Releasability of the bottom mold 15 from the molded glass container C can be improved by suppressing the temperature rise of the tip portion 37 .

Since the lower end of the shaft portion 51 of the tip portion 37 of the convex portion 36 is arranged in the cooling cavity 41, the shaft portion 51 is cooled by the cooling air. Thereby, the heat transferred from the glass container C to the head portion 52 is transported into the cooling cavity 41 by the shaft portion 51 and transferred to the cooling air flowing through the cooling cavity 41 . Thereby, the temperature of the surface of the head portion 52 of the tip portion 37 that is in contact with the glass container C can be lowered. Since the shaft portion 51 connecting the head portion 52 and the cooling cavity 41 improves the cooling effect of the tip portion 37, the tip portion 37 can be sufficiently cooled without increasing the cooling capacity of the entire bottom mold. can. This makes it possible to maintain the high temperature of the base 38 of the projection 36 . As a result, the temperature difference between the tip portion 37 and the base portion 38 is reduced.

Since the shaft portion 51 has the cooling fins 61, the heat dissipation capacity of the shaft portion 51 is increased, and the temperature of the surface of the head portion 52 in contact with the glass container C can be further reduced. A widened portion 45 is provided at the end of the receiving hole 44 on the side of the cooling cavity 41 , and a gap 56 is formed between the inner peripheral surface of the receiving hole 44 and the outer peripheral surface of the shaft portion 51 . The exposed area to 41 can be increased. Thereby, the cooling of the shaft portion 51 can be enhanced.

A receiving hole 44 is formed in the base portion 38 of the convex portion 36, a shaft portion 51 is provided in the tip portion 37 of the convex portion 36, and the shaft portion 51 is inserted into the receiving hole 44; The assembly structure of the distal end portion 37 and base portion 38 of 36 can be simplified.

Examples of the above embodiment will be described below. The example has the same configuration as the above embodiment. The first material was gray cast iron and the second material was a copper-nickel alloy. For the purpose of comparison with the examples, a bottom mold (comparative example) in which the material (second material) of the tip portion 37 of the projection 36 is made of gray cast iron and the tip portion 37 of the projection 36 and the base portion 38 are integrally formed is provided. prepared. Other configurations of the bottom mold according to the comparative example were the same as those of the bottom mold according to the example.

Molding of the glass container C was continuously performed 50 times using the bottom molds according to Examples and Comparative Examples, and immediately after that, the first measurement point (the tip portion 37 of the convex portion 36) and the second measurement point (the convex portion 36) were measured. The surface temperature of the base 38) of the portion 36 was measured. The flow rate of the cooling air (compressed air) supplied to the cooling cavity 41 was adjusted so that the surface temperature at the first measurement point was about 600.degree.

The results are shown in Table 1 below. In the bottom mold according to Example, the surface temperature at the first measurement point was 580°C, the surface temperature at the second measurement point was 540°C, and the temperature difference between the first and second measurement points was 40°C. On the other hand, in the bottom mold according to the comparative example, the surface temperature at the first measurement point was 610°C, the surface temperature at the second measurement point was 480°C, and the temperature difference between the first and second measurement points was 130°C. . In addition, when the bottom mold according to the example was used, the flow rate of the supplied cooling air was smaller than when the bottom mold according to the comparative example was used.

Although the specific embodiments have been described above, the present invention is not limited to the above embodiments and can be widely modified. For example, as shown in FIG. 4, the tip portion 37 of the convex portion 36 may be a thermally sprayed portion 71 that is thermally sprayed in the center of the base portion 38 . In this case, it is preferable to form the receiving hole 44 in the base portion 38 and close the receiving hole 44 with the sprayed portion 71 made of the second material, as in the above embodiment. Preferably, the sprayed portion is exposed to the cooling cavity 41 .

Reference Signs List 1: Molding device 10: Distributor plate 15: Bottom mold 18: Exhaust passage 23: First ventilation hole 24: Second ventilation hole 25: Bottom plate part 26: Second support hole 31: Bottom mold lower part 32: Bottom mold upper part 33: Bottom mold surface 35 : Concave portion 36 : Protruding portion 37 : Tip portion 38 : Base portion 41 : Chamber 42 : Third ventilation hole 44 : Receiving hole 45 : Widened portion 51 : Shaft portion 52 : Head portion 56 : Gap 58 : Retaining pin 59: Insertion hole 61: Cooling fin 64: Finishing mold 71: Thermal spraying part A: Central axis line C: Glass container

Claims (12)

A bottom mold that is used for blow molding to mold a glass container from a parison and molds the bottom of the glass container,
having a convex portion projecting upward from the center portion of the bottom mold and corresponding to the center portion of the bottom portion of the glass container;
The base of the convex portion is formed of a first material,
The bottom mold, wherein the tip of the projection is made of a second material having higher thermal conductivity than the first material. the base of the protrusion has a receiving hole in the center,
The tip portion of the convex portion has a shaft portion inserted into the receiving hole, and a head portion provided at one end of the shaft portion and forming a central portion of the bottom portion of the glass container. The bottom mold according to claim 1. 3. The bottom mold according to claim 2, wherein the head portion protrudes toward the glass container with respect to the base portion of the convex portion. A cooling passage through which a cooling medium flows is formed below the convex portion inside the bottom mold,
the receiving hole is connected to the cooling passage;
4. The bottom die according to claim 2, wherein the other end of said shaft portion protrudes into said cooling passage. 5. The bottom mold according to claim 4, wherein the other end of said shaft has a plurality of cooling fins. 6. The end portion of the receiving hole on the side of the cooling passage is wider than the end portion on the opposite side, and forms a gap between the receiving hole and the shaft portion. bottom type. 7. The bottom mold according to claim 6, wherein the shaft portion is press-fitted into the receiving hole. 8. The bottom mold according to claim 7, further comprising a retainer pin that extends in the radial direction of the shaft portion, penetrates through the base portion of the convex portion, and is engaged with the shaft portion. 2. The bottom mold according to claim 1, wherein the tip portion of the projection is a thermally sprayed portion thermally sprayed onto the base of the projection. The bottom mold according to any one of claims 1 to 9, wherein the first material is an iron-based material and the second material is a copper-based material. A method for manufacturing a glass container using the bottom mold according to any one of claims 1 to 10,
A step of adjusting the temperature of the tip portion and the base portion of the convex portion to 500° C. or higher and 600° C. or lower, and pressing glass having flexibility of 700° C. or higher and 1000° C. or lower against the bottom mold. A method for manufacturing a glass container. A method for manufacturing a glass container using the bottom mold according to any one of claims 1 to 10,
The temperature of the tip of the protrusion is adjusted to 550° C. or higher and 600° C. or lower, and the temperature of the base of the protrusion is adjusted to 500° C. or higher and 550° C. or lower, and the flexibility is 700° C. or higher and 1000° C. or lower. A method for manufacturing a glass container, comprising the step of pressing the glass having the above against the bottom mold.

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